Japanese Patent No. 5602616 discloses an illuminating device that sets a wavelength of one optical source out of optical sources arranged in both ends of an elongated light guiding element to include at least a part of a wavelength of the other optical source.
The illumination device 1 is configured such that illuminance of the one optical source and illuminance of the other optical source are successively changed independently with each other to gradually change from a color of the one optical source to a color of the other optical source, thus carrying out performance on an optical flow.
However, in a case of Japanese Patent No. 5602616, an illuminance distribution of each of the optical sources to the light guiding element is not definite. Therefore, it is indefinite how the light of each of the optical sources is mixed in color for optical performance, and it cannot be said that the performance effect of the light is excellent.
Accordingly, it is required to further enhance the performance effect of the light.